UNITEDSTATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C.20460

OFFICEOF WATER

SUBJECT: Interpretation of Federal Antidegradation Regulatory

Requirement

FROM:

TO: Tudor T. Davies Director

Office of Science andTechnology

Water Management Division Directors Regions I -X

Themain purpose of this memorandum is to provide guidance
onthe interpretation of the antidegradation policy in 40CFR 131.12(a) (2) asit relates to nonpoint sources. Guidance onthis subject wasrequested bythe regional water quality standards coordinators at their March 1993meeting.

This memorandumalso discusses the applicability of water quality standards to nonpoint sources, regardless of whether direct implementation mechanisms exist for nonpoint sources.

TheFederal antidegradation policy requirement is found in Section 131.12 of the water quality standards regulation (40CFR Part 131). This guidance addresses the language andintent of the Federal regulatory requirement. However, water quality standards
are State laws or regulations. It is the actual language of a State's antidegradation policy that is implemented asthe State's water quality standard. This guidance does not supersede existing State lawor regulation.

In the early years of the standards program, most States adopted EPA's regulatory language or language consistent with the regulatory requirements for antidegradation. Asthe water program hasevolved moreattention is being given toactual antidegradation policy implementation andincreasing attention to the need for controls onnonpoint sources. Although there are no Federally enforceable requirements for control of nonpoint
sources in the Clean Water Act, water quality impacts from2

nonpoint sources have become increasingly evident. Many States have asked what the antidegradation policy requires for the development and implementation of nonpoint source controls in high quality waters.

There are two components of the water quality standards regulation that are relevant to this inquiry. First, the EPA rule provides that as one condition of allowing degradation of a high quality water, "the State shall assure that there shall be achieved the highest statutory and regulatory requirements for all new and existing point sources and all cost-effective and reasonable best management practices for nonpoint source control." (40 CFR131.12(a) (2)). Second, degradation is also conditioned upon aState determination that "allowing alower water quality is necessary to accommodate important economic or social development in the area in which the waters are located." Id. (Emphasis added.)

THEISSUE

Dothose provisions REQUIRE aState to establish and implement best management practices (BMPs) for nonpoint sources before allowing degradation in high quality waters?

THEREGULATORY INTERPRETATION

Section 131.12(a) (2) does not REQUIRE;aState to establish BMPsfor nonpoint sources where such BMPrequirements do not exist.

Weinterpret Section 131.12 (a)(2) asREQUIRING States to adopt an antidegradation policy that includes aprovision that will assure that all cost-effective and reasonable BMPs established under State authority are implemented for nonpoint
sources before the State authorizes degradation of high quality waters by point sources.

Section 131.12(a)(2) does not controls on nonpoint sources. The mandate that States establish Act leaves it to the States to determine what, if any, controls on nonpoint sources are needed to provide for attainment of State water quality standards.See CWASection 319. States mayadopt enforceable requirements, or voluntary programs to address nonpoint source pollution.Id. Section 40 CFR131.12(a)(2) does not require that States adopt or implement best management practices for nonpoint sources prior to allowing point source degradation of ahigh quality water. However, States that have adopted nonpoint source controls must
assure that such controls are properly implemented before authorization is granted to allow point source degradation of water quality.3

Therationale behind the antidegradation regulatory statement regarding achievement of statutory requirements for point sources andall cost effective andreasonable BMPsfor nonpoint sources is toassure that, in high quality waters, where there are existing point ornonpoint source control compliance problems, proposed neworexpanded point sources are not allowed to contribute additional pollutants that could result in degradation. Wheresuchcompliance problems exist, it would be inconsistent with the philosophy of the antidegradation policy to authorize the discharge of additional pollutants in the absence of adequate assurance that anyexisting compliance problems will beresolved.

EPA's regulation also requires maintenance of high quality waters except where the State finds that degradation is "necessary to accommodate important economic andsocial development in the area inwhich the waters are located." (40CFR Part 131.12(a) (Emphasis added)). Webelieve this phrase should beinterpreted to prohibit point source degradation as unnecessary to accommodate important economic andsocial development if it could bepartially orcompletely prevented through implementation of existing State-required BMPs.

EPAbelieves that its antidegradation policy should be interpreted, with respect to the matters discussed in this memorandum, onapollutant-by-pollutant andwaterbody-bywaterbody basis. Forexample, degradation of ahigh quality waterbody byaproposed newBODsource prior to implementation of required BMPsonthe samewaterbody that are related to BOD loading should not beallowed. However, degradation bythe new point source of BODshould not bebarred solely onthe basis that BMPsunrelated to BODloadings, orwhich relate to other waterbodies, havenot been implemented.

EPAunderstands that implementation of best management practices is anongoing effort andthat additional EPAguidance regarding best management practices maybeneeded in the future. Also, there are statutory changes under consideration that may impact the development andimplementation of nonpoint source controls. EPAwill beaddressing such implementation issues in future guidance that is beyond the scope of this document.

TheState antidegradation policy maybeused to support State efforts for obtaining additional authority to control nonpoint sources (e.g., several States consider their water quality standards to be"self-implementing" or directly enforceable).

Werecommend that States explain in their antidegradation polices or procedures how, andtowhat extent, the State will require implementation of otherwise non-enforceable (voluntary) BMPsbefore allowing point source degradation of high quality4

waters. EPAunderstands this recommendation exceeds the Federal requirements discussed in this guidance. Forexample, nonpoint source management plans being developed under section 319of the Clean Water Act are likely to identify potential problems and certain voluntary meanstocorrect those problems. TheState should consider howthese provisions will beimplemented in conjunction with the water quality standards program.
APPLICABILITY OFWATERQUALITYSTANDARDSTONONPOINTSOURCES VERSUSENFORCEABILITY OFCONTROLS

Themain issue that this memorandumaddresses, the requirement in Section 131.21(a)(2) to implement existing nonpoint source controls before allowing degradation of ahigh quality water, is asubset ofthe broader issue of the applicability ofwater quality standards versus the enforceability of controls designed to implement standards. A discussion of the broader issue is included here with the intent of further clarifying the nonpoint source antidegradation question. In the following discussion, the central message is that water quality standards apply broadly andit is inappropriate to exempt whole classes of activities from standards andthereby invalidate that broader, intended purpose of adopted State water quality standards.

Water quality standards serve the dual function of establishing water quality goals for aspecific waterbody and providing the basis for regulatory controls. Water quality standards apply to both point andnonpoint sources. There is a direct Federal implementation mechanism to regulate point sources of pollution but noparallel Federal regulatory process for nonpoint sources. Under State law, however, States cananddo adopt mandatory nonpoint source controls.

State water quality standards play the central role in a State's water quality management program, which identifies the overall mechanism States useto integrate the various Clean Water Act water quality control elements into acoherent management framework. This includes, for example: (1) setting andrevising water quality standards for all surface waterbodies, (2) monitoring water quality to provide information uponwhich water quality-based decisions will bemade, progress evaluated, and
success measured, (3) preparing awater quality inventory report under section 305(b) which documents the status of the States' water quality, (4) developing awater quality management plan which lists the standards, andprescribes the regulatory and construction activities necessary to meetthe standards, (5) calculating total maximumdaily loads andwasteload allocations for point sources of pollution andload allocations for nonpoint
sources of pollution in the implementation of standards,(6) implementing the section 319management plan which outlines the State's control strategy for nonpoint sources of pollution, and5

(7) developing permits under Section 402.

Water quality standards describe the desired condition of the aquatic environment, and, as such, reflect any activity that affects water quality. Water quality standards have broad application and use in evaluating potential impacts of water quality from abroad range of causes and sources and are not limited to evaluation of effects caused by the discharge of pollutants from point sources. In this regard, States should have in place methods by which the State can determine whether or not their standards have been achieved (including uses, criteria, and implementation of an antidegradation policy). Evaluating attainment of standards is basic to successful application of a State's water quality standards program. In the broad application of standards, these evaluations are not limited to those activities which are directly controlled through a mandatory process. Rather, these evaluations are an important component of aState's water quality management program regardless of whether or not anenforcement procedure is in place for the activity under review.

Water quality standards are implemented through State or EPA-issued water quality-based permits and through State nonpoint
source control programs. Water quality standards are implemented through enforceable NPDESpermits for point sources and through the installation and maintenance of BMPsfor nonpoint sources. Water quality standards usually are not considered self-enforcing except where they are established as enforceable under State law. Application of water quality standards in the overall context of
awater quality management program, however, is not limited to activities for which there are enforceable implementation mechanisms.

In simple terms, applicability and enforceability are two distinctly separate functions in the water quality standards program. Water quality standards are applicable to all waters and in all situations, regardless of activity or source of degradation. Implementation of those standards maynot be possible in all circumstances; in such cases, the use attainability analysis maybe employed. In describing the desired condition of the environment, standards establish a benchmark against which all activities which might affect that desired condition are, at aminimum, evaluated. Standards serve as the basis for water quality monitoring and there is value in identifying the source and cause of aexceedance even if, at present, those sources of impact are not regulated otherwise controlled.

It is acceptable for aState to specify particular classes of activities for which no control requirements have been established in State law. It is not acceptable, however, to specify that standards do not apply to particular classes of6

activities e.g. for purposes of monitoring and assessment). To do sowould abrogate one of the primary functions of water quality standards.

If you have any additional questions, please contact David K. Sabock, Chief, Water Quality Standards Branch, 202-260- 1318.

cc: Water Quality Branch Chiefs, Regions 1-X Water Quality Standards Coordinators, Regions I -X Lee Schroer, OGC Geoffrey Grubbs, AWPD